Packet Processing Using a Multi-Port Memory

1. A method comprising: storing a packet into a packet memory at a first memory location in the packet memory; storing part of the packet used in processes performed by a lower layer processing portion and a higher layer processing portion into a second memory location in a multi-port shared memory, where a storage capacity of the second memory location is related to a storage capacity of the first memory location, the lower layer processing portion and the higher layer processing portion accessing a same memory space of the multi-port shared memory without interference; processing, via the higher layer processing portion, the part of the packet to create an updated part; appending, via the lower layer processing portion, the updated part to the packet to create a new packet; and transmitting the new packet.

2. The method of claim 1 where the lower layer processing portion includes a layer 2 processing portion.

3. The method of claim 2 where the higher layer processing portion includes a layer 3 processing portion.

4. The method of claim 1 where the part of the packet includes a header portion of the packet.

5. The method of claim 1 where the storage capacity of the second memory is 1/m of the storage capacity of the first memory.

6. The method of claim 1 where the lower layer processing portion and the higher layer processing portion access the same memory space of the multi-port shared memory via different memory buses.

7. A packet exchange, comprising: a reception processing portion of a layer for receiving a packet, storing the received packet to a packet memory, and storing a header portion of the received packet into an address of a shared memory; a processing portion of another layer for receiving the header portion, executing a network process corresponding to the header portion, updating the header portion when necessary, and storing the updated header portion into the address of said shared memory; and a transmission processing portion of the layer for combining the updated header portion received from the processing portion of the another layer and stored in said shared memory and packet information stored in said packet memory to form resultant data and transmitting the resultant data as a packet.

8. The packet exchange of claim 7 where the layer includes layer 2.

9. The packet exchange of claim 8 where the another layer includes layer 3.

10. The packet exchange of claim 7 where the transmission processing portion of the layer combines data updated by the processing portion of the another layer and stored in said shared memory and packet data stored in said packet memory, transmits the combined data, converts a packet format into a format of a third layer, and when the another layer is an Internet Protocol (IP) layer, converts an IP V4 (Version 4) packet into an IP V6 (Version 6) packet or vice versa.

11. A method comprising: processing, by a reception processing portion of a layer, a plurality of packets; processing, by a processing portion of another layer, the plurality of packets, where the processing by the processing portion of the another layer occurs after the processing by the reception processing portion of the layer; and processing, by a transmission processing portion of the layer, the plurality of packets, where processing by the transmission processing portion of the layer occurs after the processing by the processing portion of the another layer, where the transmission processing portion of the layer processes a first packet of the plurality of packets at a same time as the processing portion of the another layer processes a second packet of the plurality of packets and the reception processing portion of the layer processes a third packet of the plurality of packets, and where the reception processing portion of the layer, the processing portion of the another layer, and the transmission processing portion of the layer are connected to a shared memory via separate buses.

12. The method of claim 11 where the layer includes layer 2.

13. The method of claim 12 where the another layer includes layer 3.

14. A device comprising: a packet memory; a multi-port shared memory; a lower layer processing portion to: store the packet in the packet memory, copy a portion of the packet to the multi-port shared memory, and access the multi-port shared memory to perform lower layer processing; and a higher layer processing portion to: access the multi-port shared memory to perform higher layer processing, where the lower layer processing portion and the higher layer processing portion access the multi-port shared memory via physically different memory buses.

15. The device of claim 14 where the lower layer processing portion includes a layer 2 processing portion.

16. The device of claim 15 where the higher layer processing portion includes a layer 3 processing portion.

17. The device of claim 14 where the portion of the packet includes a header portion of the packet.

18. The device of claim 14 where the lower layer processing portion is further to: store the packet at a first memory location in the packet memory, and store the portion of the packet in a second memory location in the multi-port shared memory, where a storage capacity the second memory location relates to a storage capacity of the first memory location.